fretscale finds fret distances from the nut for stringed musical instruments based on scale length/# frets/decimal accuracy. It can output with/without a heading and with/without the remaining scale distance after each fret.

Gnofract 4D is a Gnome-based program to draw
fractals. What sets it apart from other fractal
programs (and makes it "4D") is the way that it
treats the Mandelbrot and Julia sets as different
views of the same four-dimensional fractal object.
It contains a Fractint-compatible formula
compiler, allowing it to draw an unlimited number
of fractal types, using numerous coloring options.

Hasciicam makes it possible to have live ASCII video on the Web. It captures video from a TV card and renders it into ASCII, formatting the output into an HTML page with a refresh tag or in a live ASCII window or in a simple text file as well, giving anyone that has a bttv card, a Linux box, and a cheap modem line the ability to show a live asciivideo feed that can be browsable without any need for a plugin, Java, etc.

TDFSB reads directory information and displays it
as a 3D world. cd'ing into another directory is
possible by simply walking into the assigned
sphere. It also reads images and text files and
displays their contents. It plays MP3 files and MPEG-1 videos as 3D objects.

DirectFB is a thin library that provides
developers with hardware graphics
acceleration, input device handling and
abstraction, an integrated windowing system
with support for translucent windows and
multiple display layers on top of the Linux
framebuffer device. It is a complete hardware
abstraction layer with software fallbacks for
every graphics operation that is not
supported by the underlying hardware.

FreeJ is a vision mixer: an instrument for
realtime video manipulation used in the fields of
dance and theater performance, veejaying, medical
visualization, and TV. With FreeJ, multiple layers
can be filtered through effect chains and then
mixed together. The supported layer inputs are
images, movies, live cameras, particle generators,
text scrollers, and more. The resulting video mix
can be shown on multiple and remote screens,
encoded into a movie, and streamed live to the
Internet. FreeJ can be controlled locally or
remotely from multiple places at the same time,
using a slick console interface. It can be
automated via JavaScript and operated via MIDI and
joystick.

sloop.splitter is a realtime sound effect program.
It samples sounds from any source and dissects
them. It searches for waveforms and repeats them
from one repetition to thousands. So, it generates
synthetic sounds from natural ones. The waveforms
are never deformed, only repeated, so always
natural waveforms are played, but in a more or
less synthetic way. The number of repetitions
constantly changes from one (the identical sound)
to thousands and back. It tries to show the
transition between the synthetic and the natural.